Not applicable.
Not applicable.
1. Field of the Invention
This invention relates in general to a ball joint and, more particularly, to a ball joint incorporating spherical roller elements.
2. Description of Related Art
Ball joints are used in applications where longitudinal displacement must be minimized, but where angular displacement must be tolerated. As such, the ball joint must be capable of sustaining longitudinal loads which are normally placed on the ball joint during operation. While there are many applications for ball joints, perhaps the most extensive use of ball joints is within the suspension and steering systems of automobiles.
When used in an automotive application, the ball joint consists of four primary components: the ball, the pin, the lining, and the housing. The ball and pin are usually integral, with the ball being captivated by the lining which is encapsulated within the housing. When there is angular displacement of the pin, the lining allows the ball to move within the housing to allow the pin to move to its new angular position. When longitudinal thrust is place on the pin, the thrust is transferred through the pin and into the ball where the load is then transferred to the housing by the lining.
While such ball joint designs provide the ability to allow the ball to swivel within the housing, such designs normally present high frictional torque when the ball and pin are rotated axially. This high frictional torque not only increases the effort needed to rotate the ball within the ball joint housing, but also contributes to the wear of the ball joint.
The present invention overcomes these and other problems by providing a ball joint which reduces the friction torque and thereby reduces wear to the ball joint. More specifically, the present invention resides in a ball joint which incorporates spherical rollers to reduce the rotational friction torque in the ball joint and to assist in the transfer the loads on the ball and pin of the ball joint to the ball joint housing.
In the present invention, the ball of the ball joint has at least one raceway on the exterior surface of the ball. Rolling elements in the form of spherical rollers travel upon the raceway on the ball. The liner rings of the ball joint are arcuate shaped to allow the spherical rolling elements to roll upon the surface of the liner rings. Thus, when assembled, the spherical rollers are located between the raceway of the ball and the arcuate surface of the liner rings and transfer the load placed on the ball to the housing while allowing the ball to rotate within the lining with reduced frictional torque.
Other objects and features of the present invention will be in part apparent and in part pointed out hereinafter.